#region (c) 2014 THN Solutions LLC. - All rights reserved
/*
Simplified BSD License (BSD)
THN HTTP Stack Library
Copyright (c) 2014, THN Solutions LLC. ( www.ThnSolutions.com )
Author: Nguyễn, M. Hải                 ( www.Minh-Hai.com     )
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice, this 
      list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright notice, 
      this list of conditions and the following disclaimer in the documentation 
      and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
POSSIBILITY OF SUCH DAMAGE.
*/
#endregion

#region Record of Change
//             							CHANGE HISTORY
// -------------------------------------------------------------------------------------
// |   DATE    | DEVELOPER  | DESCRIPTION                                              |
// -------------------------------------------------------------------------------------
// | 04-Nov-12 | HaiNM      | First creation.                                          |
// -------------------------------------------------------------------------------------
//
#endregion

#region Record of Audit
//             							REVIEW HISTORY
// -------------------------------------------------------------------------------------
// |   DATE    | REVIEWER   | NOTES                                                    |
// -------------------------------------------------------------------------------------
// -------------------------------------------------------------------------------------
//
#endregion

#region Using directives
using System;

using Thn;
#endregion

namespace Thn.Net.Http
{
    /// <summary>
    /// This transformer is responsible for processing incoming <see cref="IConcurrentStreamMessage"/> and procedure appropriate <see cref="IHttpRequest"/>.
    /// </summary>
#if DEBUG || TESTING
    public
#else
    public
#endif
 class IncomingHttpRequestTransformer : IMessageTransformer
    {
        #region Fields
        #endregion

        #region Properties
        #endregion

        #region Create Context
        IncomingHttpRequestTransformerContext CreateContext(IChannel channel)
        {
            IncomingHttpRequestTransformerContext result = new IncomingHttpRequestTransformerContext();
            result.Channel = channel;
            HttpRequestParser parser = new HttpRequestParser();
            result.Parser = parser;
            //parser.ParseCompleted += parser_ParseCompleted;
            //parser.ParseFailed += parser_ParseFailed;
            //parser.Tag = result;

            return result;
        }
        #endregion

        #region IMessageTransformer Members

        #region Transform
        /// <summary>
        /// Process the provided message (if necessary). If the processing is completed successfully, return the newly processed message. Otherwise, returns null.
        /// </summary>
        /// <param name="channel">The channel where the message is being sent to.</param>
        /// <param name="message">The message to be transformed.</param>
        /// <returns>If message is transformed successfully, return the new message. Otherwise, returns null.</returns>
        object IMessageTransformer.Transform(IChannel channel, object message)
        {
            object result = null;

            if (message is IConcurrentByteStreamMessage)
            {
                IConcurrentByteStreamMessage pm = (IConcurrentByteStreamMessage)message;

                //retrieve my context
                IncomingHttpRequestTransformerContext context = channel.Session.Parameters[this] as IncomingHttpRequestTransformerContext;
                if (context == null)
                {
                    #region Context not available -> create it

                    context = CreateContext(channel);

                    //store it for later retrieval
                    channel.Session.Parameters[this] = context;

                    #endregion
                }
                #region Defensive tracing
                else
                {
                    //found, move on
                }
                #endregion

                //let the parser process
                IHttpContent content;
                Exception error;
                if (context.Parser.TryProcess(pm.Reader, out content, out error))
                {
                    #region Parsed successfully

                    result = (IHttpMessage)content;

                    #endregion
                }
                else
                {
                    #region Parsing failed
                    #endregion
                }
            }
            #region Defensive tracing
            else
            {
                //I don't understand this message, skip
            }
            #endregion

            //return result
            return result;
        }
        #endregion

        #endregion

        #region Constructors
        /// <summary>
        /// Default constructor.
        /// </summary>
        public IncomingHttpRequestTransformer()
        { }
        #endregion
    }
}
